> The game mechanics were literally a rigged slot machine.
This is an accurate description. So many games where people have to pay for the chance to get something. It's even worse than actual gambling since the prize isn't even money. All people get is some numbers in a database.
Another oppressive feature found in most exploitative games is the timer. Through a timer, the progression of free players is rate-limited. There's almost always some kind of resource that's used up whenever players do anything and when they run out of it the timer reveals itself. The game refills the resource on a regular basis.
This creates habits in players. People start out playing normally and next thing they know they're setting alarms to wake them up at 3 AM to do game tasks because that's when the timer resets. This is done deliberately with the goal to increase the number of players who login every day through a mix of positive and negative reinforcement. The timed refills themselves act as a periodic reward which is simple enough. More insidious however is how usually the timers will not start counting down to the next reward until players play the game. Every second the timer is not running is wasted and delays the next reward.
Paying customers can reset this timer at will. They are therefore able to progress at an uncapped rate. This implies the game's true form is a spending competition: the whale who gives the most money to the company for the longest time will win.
Video game addiction is already a recognized medical diagnosis. I have no doubt this trash is at least partly responsible for that. The reputation of the games industry is only gonna go downhill from there.